Question: If $x \bigtriangleup y = 2x^{2}+y^{2}$ and $x \circledcirc y = 7x-y$, find $-2 \circledcirc (0 \bigtriangleup 1)$.
First, find $0 \bigtriangleup 1$ $ 0 \bigtriangleup 1 = 2(0^{2})+1^{2}$ $ \hphantom{0 \bigtriangleup 1} = 1$ Now, find $-2 \circledcirc 1$ $ -2 \circledcirc 1 = (7)(-2)-1$ $ \hphantom{-2 \circledcirc 1} = -15$.